According to leaks and some leaked software code in iOS 7, the fingerprint sensor will allow you to log into the phone with just a swipe of your finger. Other improvements are said to include a faster processor and a better camera. So if you are holding out for an iPhone with a bigger screen than the current 4-inch display, it looks like you are going to have to wait a bit longer.
The biggest news at the event might not even be the hardware. In June, Apple previewed iOS 7, the next version of the iPhone and iPad software that looks radically different. Everything has been redesigned with new colors and icons and there are new features too, including a Command Center for easy access to settings and a new camera app. Siri also has a different voice. Apple will announce the release date of the software at the event, which will likely be the week of the iPhone launch. Apple has already said that iOS 7 would be out this fall for the iPhone 4, iPhone 4S and iPhone 5.
Source: ABC